Systems and methods for transporting and assembling segmented wind turbine blades

ABSTRACT

Systems and methods for transporting and assembling segmented wind turbine blades are disclosed. A system in accordance with a particular embodiment includes multiple transport devices that are each moveable as a unit from a blade fabrication site to a blade assembly site, and that have corresponding carriers positioned to carry corresponding spanwise segments of a wind turbine blade. The system can still further include a guide structure carried by at least one of the transport devices and coupled to a corresponding one of the carriers, with a motion path aligned with a corresponding blade axis. The guide structure can be positioned to guide the corresponding carrier along the motion path toward the other transport devices, e.g., to facilitate assembly of the blade segments.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of International PatentApplication No. PCT/US2010/035957, filed May 24, 2010, entitled SYSTEMSAND METHODS FOR TRANSPORTING AND ASSEMBLING SEGMENTED WIND TURBINEBLADES, which claims priority to U.S. Provisional Application No.61/180,812, and U.S. Provisional Application No. 61/180,816, both filedMay 22, 2009 and both incorporated herein by reference.

TECHNICAL FIELD

The present disclosure is directed generally to systems and methods fortransporting and assembling segmented wind turbine blades, includingwind turbine blades having multiple segments aligned along a spanwiseaxis.

BACKGROUND

As fossil fuels become scarcer and more expensive to extract andprocess, energy producers and users are becoming increasingly interestedin other forms of energy. One such energy form that has recently seen aresurgence is wind energy. Wind energy is typically harvested by placinga multitude of wind turbines in geographical areas that tend toexperience steady, moderate winds. Modern wind turbines typicallyinclude an electric generator connected to one or more wind-driventurbine blades, which rotate about a vertical axis or a horizontal axis.

In general, larger (e.g., longer) wind turbine blades produce energymore efficiently than do short blades. Accordingly, there is a desire inthe wind turbine blade industry to make blades as long as possible.However, long blades create several challenges. Such blades are heavyand therefore have a significant amount of inertia, which can reduce theefficiency with which the blades produce energy, particularly at lowwind conditions. In addition, long blades are difficult to manufactureand in many cases are also difficult to transport. Accordingly, thereremains a need for large, efficient, lightweight wind turbine blades,and suitable methods for transporting and assembling such blades.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially schematic, isometric illustration of a windturbine system having blades configured in accordance with an embodimentof the disclosure.

FIG. 2 is a partially schematic, elevation view of a wind turbine bladehaving a segmented structure in accordance with an embodiment of thedisclosure.

FIG. 3 is a partially schematic, side elevation view of an arrangementof transport platforms for assembling segmented wind turbine blades inaccordance with an embodiment of the disclosure.

FIG. 4 is a partially schematic, end isometric view of a guide structurehaving a support carrying a wind turbine blade segment for alignment andattachment in accordance with an embodiment of the disclosure.

FIG. 5 is an enlarged, partially schematic illustration of a portion ofthe support shown in FIG. 4.

FIG. 6A is an enlarged, partially schematic illustration of anotherportion of the support shown in FIG. 4.

FIG. 6B is an enlarged, partially schematic illustration a portion ofthe support shown in FIG. 4 having a guide roller arrangement configuredin accordance with another embodiment of the disclosure.

FIG. 7A is a partially schematic, isometric illustration of a guidestructure having a motion device configured in accordance of anembodiment of the disclosure.

FIG. 7B is a partially schematic, isometric illustration of the guidestructure shown in FIG. 7A with the carrier removed in accordance of anembodiment of the disclosure.

FIG. 8 is a partially schematic, side elevation view of the guidestructure shown in FIG. 7A.

FIG. 9 is a partially schematic, isometric illustration of a supportcarrying a portion of a wind turbine blade segment in accordance with anembodiment of the disclosure.

FIG. 10A is a partially schematic, isometric illustration of a platformalignment system configured in accordance with an embodiment of thedisclosure.

FIGS. 10B and 10C are partially schematic illustrations of transportplatforms positioned in preparation for joining wind turbine bladesegments in accordance with a particular embodiment of the disclosure.

FIG. 10D is a partially schematic, side elevation view of two opposingend portions of wind turbine blade segments positioned on adjacenttransport platforms prior to assembly in accordance with an embodimentof the disclosure.

FIG. 11A is a partially schematic, side elevation view of a wind turbineblade spar having multiple portions, each with layers that terminate atstaggered locations to form a non-monotonically varying bond line.

FIG. 11B is an illustration of an embodiment of the structure shown inFIG. 11A with clamps positioned to prevent or limit delamination inaccordance with an embodiment of the disclosure.

FIG. 11C is an enlarged illustration of a portion of the spar shown inFIG. 6B.

FIG. 11D is a partially schematic, isometric view of two opposing endportions of a wind turbine blade spar prior to joining.

FIG. 11E is a partially schematic, isometric view of the two opposingspar end portions of FIG. 11D after joining, in accordance with anembodiment of the disclosure.

FIG. 12 is a partially schematic, isometric view of two opposing endportions of wind turbine blade segments prior to joining in accordancewith an embodiment of the disclosure.

FIG. 13 illustrates an apparatus for applying heat and/or pressure to abonded wind turbine blade spar joint in accordance with an embodiment ofthe disclosure.

FIGS. 14A-14F illustrate systems and methods for assembling andtransporting wind turbine blades in accordance with further embodimentsof the disclosure.

DETAILED DESCRIPTION

The present disclosure is directed generally to systems and methods forefficiently transporting and assembling wind turbine blade sections.Several details describing structures or processes that are well-knownand often associated with such systems and methods, but that mayunnecessarily obscure some significant aspects of the disclosure, arenot set forth in the following description for purposes of brevity.Moreover, although the following disclosure sets forth severalembodiments, several other embodiments can have different configurationsor different components than those described herein. In particular,other embodiments may have additional elements or may lack one or moreof the elements described below with reference to FIGS. 1-14F.

FIG. 1 is a partially schematic, isometric illustration of an assembledwind turbine system 100 that includes a wind turbine 103 having blades110 configured in accordance with an embodiment of the disclosure. Thewind turbine 103 includes a tower 101 (a portion of which is shown inFIG. 1), a housing or nacelle 102 carried at the top of the tower 101,and a generator 104 positioned within the housing 102. The generator 104is connected to a shaft having a hub 105 that projects outside thehousing 102. The blades 110 each include a hub attachment portion 112 atwhich the blades 110 are connected to the hub 105, and a tip 111positioned radially or longitudinally outwardly from the hub 105. In anembodiment shown in FIG. 1, the wind turbine 103 includes three blades110 connected to a horizontally-oriented shaft. Accordingly, each blade110 is subjected to cyclically varying loads as it rotates between the12:00, 3:00, 6:00 and 9:00 positions, because the effect of gravity isdifferent at each position. In other embodiments, the wind turbine 103can include other numbers of blades connected to a horizontally-orientedshaft, or the wind turbine 103 can have a shaft with a vertical or otherorientation. In any of these embodiments, the blades 110 can havestructures configured in accordance with the arrangements described infurther detail below with reference to FIG. 2.

FIG. 2 is a partially schematic, partially cut-away illustration of oneof the blades 110 shown in FIG. 1. The blade 110 extends outwardly in aradial direction from an inner region 113 that includes the hubattachment portion 112, to an outer region 114 that includes the tip111. In particular embodiments, the internal structure of the blade 110can be different at the inner region 113 than at the outer region 114.For example, the inner region 113 can include a truss structure 140formed from a plurality of longitudinally extending beams or spars 170,chordwise extending ribs 142, and truss members 143 connected betweenthe spars 170 and the ribs 142. The truss structure 140 can besurrounded by a skin 115 (most of which is removed in FIG. 2) thatpresents a smooth, aerodynamic surface to the wind during operation. Theouter region 114 can include a non-truss structure. As used herein, theterm “truss structure” refers generally to a load-bearing structure thatincludes generally straight, slender members forming closed shapes orunits (e.g., triangular units). The term “non-truss structure” refersgenerally to a load-bearing structure having an arrangement that doesnot rely on, or does not primarily rely on, straight slender membersforming closed-shape units for strength.

In a particular aspect of an embodiment shown in FIG. 2, the blade 110includes three segments 116, shown as a first segment 116 a, a secondsegment 116 b, and a third segment 116 c. The first and second segments116 a, 116 b can each have the truss structure 140 described above, andthe third segment 116 c can have a non-truss structure. Accordingly, theblade 110 can have a truss structure for the inner two-thirds of itsspan, and a non-truss structure for the outer one-third of its span. Inother embodiments, these values can be different, depending, forexample, on the size, shape and/or other characteristics of the blade110. In still further embodiments, the blade 110 can have other numbersand/or arrangements of segments. For example, the blade 110 can have anon-truss structure for the majority of the length of each segment 116,and a truss structure at the joints between neighboring sections.Further details of such an arrangement are described in co-pending U.S.Application No. ______, titled “Segmented Wind Turbine Blades with TrussConnection Regions, and Associated Systems and Methods,” filedconcurrently herewith and incorporated herein by reference. The segments116 can be manufactured individually at one or more sites, and thenconnected to each other at a manufacturing facility, or at an end userinstallation site. For example, the segments 116 can each be sized to becarried by a 53-foot or other suitably sized container, trailer, orother transport device for shipment, as will be described in furtherdetail later. In other embodiments, one or more of the segments (e.g.,the first segment 116 a and the second segment 116 b) can be builtentirely at the installation site.

In any of the foregoing embodiments, individual segments 116 can includeribs 142, truss members 143, and portions of the spars 170 that extendfor the length of the segment 116. The segments 116 can be joined toeach other by joining adjacent spar portions, e.g., as discussed laterwith reference to FIGS. 11A-13, and connecting truss members 143 betweenthe segments 116. In any of these embodiments, the skin 115 can be laidup on the truss structure 140 with or without forming a joint at theinterface between adjacent segments 116. For example, the spar portionscan be joined at a location between two neighboring ribs 142, and arelatively small panel of skin 115 can be laid over the spar joint andthe two neighboring ribs 142. The neighboring ribs 142 can be spacedapart by about one meter in one embodiment, and by other values in otherembodiments. Larger panels of the skin 115 can be laid inboard andoutboard of the small panel. In another embodiment, the skin 115 canhave joints not aligned with spar joints, or no spanwise joints, and canbe laid up as a continuous element. In any of these embodiments, theskin 115 can be attached (e.g., bonded or fastened, adhesively,ultrasonically or otherwise) to the ribs 142 alone, or to the ribs 142and the spars 170. In many of these embodiments, the truss structure 140can serve as primary structure for carrying shear and bending loads inthe blade 110. Further details of several embodiments of the blade 110are described in co-pending PCT Application No. US09/66875, filed Dec.4, 2009, and incorporated herein by reference.

FIG. 3 is a partially schematic, side elevation view of an arrangementfor transporting, aligning, and assembling the blade segments describedabove with reference to FIG. 2. In one aspect of this embodiment, thearrangement can include multiple transport platforms or devices 121. Forexample, the arrangement can include three such platforms, shown in FIG.3 as a first transport platform 121 a, a second transport platform 121b, and a third transport platform 121 c. The transport platforms 121 caninclude truck-drawn highway-compatible trailers, as shown in aparticular embodiment illustrated in FIG. 3. In other embodiments, thetransport platforms 121 can include other devices e.g., railroad cars,containers, dollies, trolleys, carts, or barges. In any of theseembodiments, each of the transport platforms 121 can carry correspondingblade segments 116, two of which (the first and third segments 116 a,116 c) are shown in FIG. 3. The blade segments 116 can be assembledblade segments, e.g., at least partially assembled blade segments.Accordingly, the blade segments are approximately full length, thoughthey may undergo additional assembly steps after arriving at a finalassembly site. One or more of the transport platforms 121 can carry aguide structure 122 (or portions of the guide structure 122) which isused to align the corresponding blade segments 116 with each other andmove the corresponding blade segments 116 into position for joining. Ina particular embodiment shown in FIG. 3, the guide structure 122 caninclude multiple supports 123 carried by one or more of the transportplatforms 121. For example, each transport platform 121 can include twosupports 123, one positioned at each end of a corresponding one of theblade segments 116. In general (e.g., except for the support 123 locatedat the hub attachment portion 112 of the first blade segment 116 a), thesupports 123 can be axially offset from the ends of the blade segmentsto which they are attached. Accordingly, neighboring blade segments canoverhang the supports 123, thus preventing the supports 123 frominterfering with each other when the neighboring blade segments aremoved toward each other for attachment. Each transport platform 121 a,121 b, 121 c can carry supports 123 that move the corresponding bladesegment along a corresponding axial motion path A1, A2, A3,respectively. Further details at this arrangement are described belowwith reference to FIGS. 4-10C and 14A-14F.

FIG. 4 is a partially schematic end view of the first blade segment 116a shown in FIG. 3, carried by two supports 123. Many of the followingfeatures are common to both supports 123, but are shown and described inthe context of the near support 123 shown in FIG. 4. The support 123 caninclude a base 124 having one or more axial guides 125 (two are shown inFIG. 4). The support 123 can further include a first portion 126 carriedby the base 124, and a second a portion 127 carried by the first portion126. The first portion 126 can be movable relative to the base 124 alonga restricted axial guide path A1, and the second portion 127 can bemovable relative to the first portion 126 along a restricted lateralguide path L. Accordingly, the first portion 126 can include one or morelateral guides 128 (two are shown in FIG. 4) that facilitate the motionof the second portion 127 along the lateral guide path L. The secondportion 127 in turn supports a carrier 180 that is releasably engagedwith the first blade segment 116 a. In a particular aspect of thisembodiment, the carrier 180 includes two engagement portions 181, eachof which is engaged with a flange 117 at the hub attachment portion 112of the first blade segment 116 a. The engagement portions 181 can beattached to the flange 117 with bolts, pins, or other suitable,releasable attachment devices. In any of these embodiments, the support123 can facilitate both lateral and axial motion of the blade segment116 a, allowing it to be aligned with and then attached to a matingblade segment.

In a particular embodiment shown in FIG. 4, both of the supports 123move along the same axial guide path A1. In other embodiments, thesupports 123 may be laterally offset from each other, and mayaccordingly move along different axial guide paths. In such cases, thetwo axial guide paths associated with a single blade segment may beparallel to prevent binding, and/or the associated supports may have arotational degree of freedom. Such an embodiment may be used for bladesegments (such as the third blade segment 116 c shown in FIG. 3) thathave a significant amount of lateral or chordwise offset from one end ofthe segment to the other.

FIG. 5 is an enlarged isometric illustration of part of the support 123shown in FIG. 4. As shown in FIG. 5, the second portion 127 of thesupport 123 includes multiple roller assemblies 150 (one of which isvisible in FIG. 5) that facilitate the lateral motion of the secondportion 127 along the lateral guides 128 carried by the first portion126. The first portion 126 includes multiple roller assemblies 150 thatfacilitate axial motion of the first portion 126 along the axial guides125 carried by the base 124. Each of the roller assemblies 150 caninclude a bracket 151 carrying one or more rollers, including a loadroller 152. The load rollers 152 bear the weight (or a majority of theweight) of the structure to which they are attached, and transmit loadsto the corresponding guide below. The roller assemblies 150 can alsoinclude guide rollers 153 described further below with reference toFIGS. 6A-6B.

Referring now to FIG. 6A, the roller assembly 150 can include multipleguide rollers 153 that engage with the corresponding guide along whichthe roller assembly 150 moves (e.g., the axial guide 125 as shown inFIG. 6A). In a particular aspect of this embodiment, the axial guide 125can include a C-channel or I-beam, and the guide rollers 153 can engagean inner surface of the upwardly facing flanges of the axial guide 125.In other embodiments, other arrangements can be used to guide the motionof the first portion 126 relative to the base 124. For example, as shownin FIG. 6B, the guide rollers 153 can be positioned at the outersurfaces of the upwardly facing flanges of the axial guide 125. In anyof these embodiments, the guides 125, 128 and the associated rollerassemblies 150 are positioned to permit motion that is restricted orlimited to be along only the axial guide path A1 and the lateral guidepath L, respectively.

FIG. 7A is a partially schematic, isometric illustration of anembodiment of the support 123 illustrating selected features in additionto those described above with reference to FIGS. 4-6B. In one aspect ofthis embodiment, the support 123 can include a carrier 780 havingvertically upstanding members carrying engagement portions 781positioned to engage laterally outwardly facing surfaces of acorresponding blade segment, as will be described further below withreference to FIG. 9. The support 123 can also include a motion device160 that facilitates relative motion between the components of thesupport 123.

In an embodiment shown in FIG. 7A, the motion device 160 can facilitatemotion of the components along three orthogonal axes. For example, themotion device 160 can include a base height adjuster 161 that moves thebase 124 in a generally vertical direction relative to the transportplatform 121, an axial motion actuator 162 that moves the first portion126 relative to the base 124 along the axial guide path A1, and alateral motion actuator 163 that moves the second portion 127 relativeto the first portion 126 along the lateral guide path L. The motionprovided by the motion device 160 can be fully manual, fully powered, ora combination of the two. For example, the base height adjustor 161 caninclude multiple threaded studs 166 located at several locations aroundthe base 124, which are manually rotated to adjust the height of thebase 124 and/or adjust the planarity of the base 124. The axial motionactuator 162 can include a motor or other powered device carried by thebase 124 and operatively coupled to the first portion 126 to drive thefirst portion 126 along the axial guides 125. The lateral motionactuator 163 can include a motor or other powered device carried by thefirst portion 126 and operatively coupled to the second portion 127 todrive it along the lateral guides 128. Accordingly, the motion device160 can be used to move the carrier 780 to a position and orientationsuitable for connecting the blade segment (not shown in FIG. 7A) with aneighboring blade segment.

In a particular embodiment, once the carrier 780 has the desiredposition, the resistance provided by the threads of the studs 166 canprevent the carrier 780 from changing its elevation. Optionally, thestuds 166 can be further secured, e.g., with locknuts. Similarly, theresistance provided by the windings and/or internal gearing of the axialmotion actuator 162 and the lateral motion actuator 163 can prevent thecarrier 780 from moving from the desired position in the axial andlateral directions, respectively. In other embodiments, separate lockingdevices can be used for this purpose.

In any of the foregoing embodiments, the motion device 160 can also beautomated. For example, the motion device 160 can include a processor(e.g., a computer-based controller), and an input device. An operatorcan input a desired location and/or orientation for the carrier 780, andthe motion device 160 can automatically drive the carrier 780 to thedesired location and/or orientation using one or more sensors (e.g.,position sensors) in a closed loop arrangement. In still furtherembodiments, the actuators 162, 163 can be removable, so that they canbe moved from one portion of a support 123 to another, or from onesupport 123 to another, thereby reducing the number of actuatorsrequired to position the blade segments.

As shown in FIG. 7B, the support 123 can be deliberately configured toallow particular elements to be rapidly assembled and disassembledduring normal use. For example, the carrier 780 can be removed from restof the support 123 during transit. In particular, the carrier 780 can belifted away from second portion 127 (including the roller assemblies 150engaged with the lateral guides 128), the first portion 126, and thebase 124. The carrier 780 can then be placed on a transport platformwithout the roller assemblies 150 potentially allowing the carrier 780to move. When the carrier 780 is to be moved relative to the transportplatform prior to assembling the associated blade segments, the firstportion 126, second portion 127 and base 124 can be slipped under thecarrier 780 as a unit to allow the carrier 780 to move.

FIG. 8 is a partially schematic, side elevation view of a portion of thesupport 123 shown in FIGS. 7A-7B, illustrating further details of aparticular embodiment of the motion device 160. As shown in FIG. 8, theaxial motion actuator 162 can be coupled to the first portion 126 with adrive link 164 that allows for motion in two opposing directions alongthe axial guides 125. In a particular aspect of this embodiment, theaxial motion actuator 162 includes a rotary motor having a shaftconnected to a drive sprocket 165 a which drives a chain connected atone end to one side of the first portion 126. The opposite end of thechain is wrapped around a guide sprocket 165 b and connected to theopposite end of the first portion 126. In other embodiments, the drivelink 164 can include other devices, for example, a direct drive device.The lateral motion actuator 163 can be coupled to the second portion 127with a similar drive link.

FIG. 9 is a partially schematic, isometric illustration of the support123 releasably attached to the third blade segment 116 c described abovewith reference to FIG. 2. In one aspect of this embodiment, theengagement portions 781 are attached directly to a corresponding rib 142of the blade segment 116 c. In another embodiment, the engagementportions 781 are attached to a structure carried by the rib 142, e.g.one of the truss attachment members described in co-pending PCTApplication US09/66875, previously incorporated herein by reference. Inany of these embodiments, the engagement portions 781 can be releasablyattached to the third blade segment 116 c with threaded fasteners orother suitable structures. Accordingly, a portion of the skin 115overlying this portion of the blade segment 116 c can be removed oromitted while the blade segment 116 c is carried by the support 123.After the support 123 has been disconnected from the blade segment 116 cduring an assembly and installation process, the missing skin portioncan be attached in place over the rib 142. Alternatively, the skin 115can extend over the rib 142, but can have one or more holes that receivethe threaded fasteners. These holes can be filled after the support 123has been disconnected.

As is also shown in FIG. 9, the supports 123 can be attached to thethird blade segment 116 c before the blade segment 116 c is placed on acorresponding transport platform 121 c (FIG. 3). For example, thesupports 123 or the carriers 780 (one of which is visible in FIG. 9) caneach be lifted with a forklift, overhead crane or other suitable deviceand then placed on the transport platform 121 c while attached to thethird blade segment 116 c. In another embodiment, the support 123 canfirst be placed on the transport platform 121 c, and the third bladesegment 116 c can then be attached to the supports 123. Either of theforegoing arrangements can be used for any of the blade segments 116a-116 c.

In a particular embodiment, the carrier 780 is detached from the secondportion 127, the first portion 126 and the base 124 before the bladesegment 116 c is placed on the transport platform, as described abovewith reference to FIG. 7B. Accordingly, the carrier 780 can restdirectly on the transport platform while the blade segment 116 c istransported to the assembly site, without allowing motion along theaxial motion path A3 or the lateral motion path L. When the transportplatform reaches the final assembly site, the carrier 780 can be liftedwhile the rest of the support 123 is re-inserted below the carrier 780.The support 123 is then ready for positioning and alignment. In otherembodiments, other arrangements can be used to restrict the carrier 780from moving. For example, the roller assemblies 150 (FIG. 7B) can belocked or retracted during transit. An advantage of embodiments in whichthe base 124, first portion 126 and second portion 127 are removed as aunit is that this part of the support 123 can be a modular unit, and canbe moved from one support 123 to another, thus reducing the number ofsuch modular units required to position a set of blade segments.

FIG. 10A is a partially schematic, isometric illustration of a platformalignment system 190 used to align the three transport platforms 121 a,121 b, 121 c described above with reference to FIG. 3. For purposes ofillustration, the guide structures 122 and blade segments 116 describedabove are not shown in FIG. 10A. In a particular aspect of theillustrated embodiment, the platform alignment system 190 can includeone or more platform height adjustors 191. For example, the platformheight adjustors 191 can include hydraulic cylinders, pneumaticcylinders, jack screws, or other devices positioned at one or morelocations of each of the transport platforms 121 to adjust the height ofthe platforms, as well as the tilt of the platforms 121. The platformheight adjustors 191 can be adjusted manually or automatically inresponse to an indication that the corresponding transport platforms 121are not at an appropriate height or tilt orientation. To provide thisinput, the platform alignment system 190 can include an emitter 192 thatemits radiation received by one or more receivers 193 located at thetransport platforms 121. For example, the emitter 192 can include alaser that emits a laser beam and rotates to produce a laser plane 194.The receiver 193 can include multiple receiver elements 195 carried byeach of the transport platforms 121. In a particular embodiment, eachtransport platform 121 can include a receiver element 195 located ateach corner of the transport platform 121. Accordingly, when the emitter192 is activated, and produces the radiation plane 194 at a desiredheight and orientation (e.g., horizontal), the operator can adjust theplatform height adjustors 191 until each of the receiver elements 195carried by each of the transport platforms 121 indicates that thetransport platform is at the correct height and orientation. Thisprocess can also be automated so as to operate in a closed-loop fashionbased on inputs from the receiver elements 195.

In other embodiments, the alignment system can have other arrangements.For example, the alignment system 190 can include multiple emitters 192,and/or a single receiver 193. In still further embodiments, thealignment system can include components that do not rely on emitting orreceiving radiation for suitable operation.

As described above, the platform alignment system 190 can be used toalign each of the transport platforms 121 relative to the others in agenerally horizontal or other desired plane. In addition, each of thetransport platforms 121 can be aligned axially. For example, each of thetransport platforms 121 a-121 c can include a corresponding axial guidepath A1-A3 along which the corresponding blade segment 116 is moved. Ina particular embodiment, each of the axial guide paths A1-A3 is alignedalong a common axis. In other embodiments, however, the guide paths maybe angularly offset from each other, depending upon the desiredorientation of the plane at the interface between the neighboring bladesegments. Also, as discussed above with reference to FIG. 4, theindividual supports carried by each of the transport platforms 121 maymove along different (though typically parallel) guide paths, dependingupon the shape of the blade segment carried by the supports. In any ofthe foregoing embodiments, the platform alignment system 190 may also beconfigured to align each of the axes A1-A3 relative to each other. Inother embodiments, however, an operator can adequately align the axesA1-A3 visually. The blade segments carried by the platforms may be morefinely aligned using the lateral motion actuators 163 described above.

FIGS. 10B and 10C illustrate the transport platform 121 a-c aligned toattach the corresponding blade segments 116 a-116 c. For purposes ofillustration, the first and second blade segments 116 a, 116 b are shownin FIGS. 10B and 10D without the skins attached. The skins can beattached either before or after the blades are shipped to an assemblysite via the transport platforms 121. As shown in FIGS. 10B-10C thefirst and second axial guide paths A1 and A2 are co-linear, and thethird guide path A3 is offset due to the curvature of the blade 110.Once the transport platforms 121 are properly aligned with each other,the corresponding blade segments carried by the transport platforms 121may be attached. In a particular embodiment in which more than twotransport platforms 121 are used to carry the requisite number of bladesegments, two blade segments may be connected to each other beforeadding additional segments. For example, the first and second segments116 a, 116 b carried by the first and second transport platforms 121 a,121 b, respectively can be connected to each other before connecting thethird blade segment 116 c carried by the third transport platform 121 cto the assembled first and second segments. In such cases, all threetransport platforms 121 a-121 c can be initially aligned with eachother, and the connection between neighboring segments can be completedsequentially. In another embodiment, the first two transport platforms121 a-121 b can be aligned with each other and the associated segments116 a, 116 b connected, and then the third transport platform 121 c canbe aligned with the first two transport platforms 121 a-121 b while thethird segment 116 c connected to the assembled first and secondsegments. In other embodiments, the transport platforms 121 may bealigned in other manners, and/or the blade segments may be connected inother sequences.

FIG. 10D is a side elevation view of a portion of the first bladesegment 116 a and the second blade segment 116 b positioned oncorresponding first and second transport platforms 121 a, 121 b. As thisview illustrates, each blade segment 116 a, 116 b includes multiplespars 170, e.g., a first spar 170 a, a second spar 170 b and a thirdspar 170 c. Each spar 170 has a first end portion 171 a at the firstsegment 116 a and a second end portion 171 b at the second segment 116b. The first end portions 171 a of the first blade segment 116 a arealigned with the corresponding second end portions 171 b of the secondblade segment 116 b. In this configuration, the first and second bladesegments 116 a, 116 b are ready to be joined together as described belowwith reference to FIGS. 11A-13.

FIG. 11A is a partially schematic, side elevation view of a jointbetween the first and second end portions 171 a, 171 b of arepresentative spar 170. The joint can be formed along anon-monotonically varying (e.g., zig-zagging) bond line 176. Such a bondline 176 is expected to produce a stronger bond between the first andsecond portions 171 a, 171 b than is a straight or diagonal bond line.

The first portion 171 a can include multiple, stacked, laminated firstlayers 172 a, and the second portion 171 b can include multiple,stacked, laminated second layers 172 b. In another embodiment, thelayers 172 a, 172 b can be made in one piece without gluing. In aparticular embodiment, the layers 172 a, 172 b can be formed from aunidirectional fiber material (e.g., fiberglass or a carbon fiber) and acorresponding resin. Each of the layers 172 a, 172 b can be formed froma single ply or multiple plies (e.g., six plies). The layers 172 a, 172b can be prepared layers, hand lay-ups, pultrusions, or can be formedusing other techniques, e.g., vacuum-assisted transfer moldingtechniques. The first layers 172 a terminate at first terminations 173a, and the second layers 172 b terminate at second terminations 173 b.Neighboring terminations 173 a, 173 b located at different positionsalong a thickness axis T can be staggered relative to each other along aspan axis S to create the zig-zag bond line 176. This arrangementproduces projections 174 and corresponding recesses 175 into which theprojections 174 fit. In a particular aspect of this embodiment, eachlayer has a termination that is staggered relative to its neighbor,except where the bond line 176 changes direction. At such points, twoadjacent layers can be terminated at the same location and bonded toeach other, to prevent a single layer from being subjected to increasedstress levels. The zig-zag bond line 176 can be symmetric, as shown inFIG. 11A, or asymmetric in other embodiments. In still furtherembodiments, the bond line 176 can be scarfed or can have a zig-zagshape in a direction transverse to the plane of FIG. 11A, as describedfurther in PCT Application US09/66875, previously incorporated herein byreference.

During a representative manufacturing process, each of the first layers172 a are stacked, bonded and cured, as are each of the second layers172 b, while the two portions 171 a, 171 b are positioned apart fromeach other. The layers 172, 172 b can be pre-cut before stacking so thatwhen stacked, they form the recesses 175 and projections 174. After thetwo portions 171 a, 171 b have been cured, the recesses 175 and/orprojections 174 can be coated and/or filled with an adhesive. The twoportions 171 a, 171 b are then brought toward each other so thatprojections 174 of each portion are received in corresponding recesses175 of the other. The joint region can then be bonded and cured.

FIG. 11B is an illustration of a spar 170 having a bond line 176generally similar to that described above with reference to FIG. 11A. Asis also shown in FIG. 11B, the spar 170 can include one or more clampsor straps 177 that are positioned at or near the bond line 176. Theclamps 177 can be positioned to prevent or halt delamination that mightresult between any of the layers in the composite spar 170. For example,as shown in FIG. 11C, if a potential delamination 178 begins between twolayers 172 a, the compressive force provided by the clamp 177 canprevent the delamination 178 from spreading further in a span-wisedirection. The clamp 177 can be positioned where it is expected that thepotential risk of delamination is high, e.g., at or near the termination173 of the outermost layers 172 a, 172 b shown in FIG. 11B. In otherembodiments, the function provided by the clamps 177 can be provided byother structures, e.g., the truss attachment members described furtherin PCT Application US09/66875, previously incorporated herein byreference.

FIG. 11D is an enlarged isometric view illustrating a third end portion171 c and an opposing fourth end portion 171 d of the second spar 170 b(also shown in FIG. 10D) prior to being joined together. As describedabove with reference to FIG. 11A, the second spar 170 b can be formedfrom a plurality of layers 172 (e.g., first layers 172 a and secondlayers 172 b). In the illustrated embodiment, the first layers 172 aproduce first projections 174 a and corresponding first recesses 175 a.Similarly, the second layers 172 b produce second projections 174 b andcorresponding second recesses 175 b. The corresponding projections 174and recesses 175 form a staggered, zig-zag bond line between theopposing spar end portions 171 c and 171 d when they are subsequentlyjoined together as illustrated in FIG. 11E.

FIG. 12 is an enlarged, partially schematic isometric view illustratinga method of joining the first blade segment 116 a to the second bladesegment 116 b in accordance with an embodiment of the disclosure. Asthis view illustrates, the opposing end portions 171 of thecorresponding spars 170 are initially separated from each other but areaxially aligned. Referring first to the second spar 170 b, a first trussattachment member 150 a on the first blade segment 116 a can include afirst lug or truss attachment portion 154 a having a first aperture 1202a. Similarly, the opposite second truss attachment member 150 b on thesecond blade segment 116 b can include a corresponding second trussattachment portion 154 b having a second aperture 1202 b. Third andfourth truss attachment members 150 c, 150 d on the first spar 170 a,and fifth and sixth truss attachment members 150 e, 150 f on the thirdspar 170 c, can also include similar truss attachment portions havingcorresponding apertures.

To join the first blade segment 116 a to the second blade segment 116 b,a push/pull device 1210 (e.g., a manual or automatic spreader bar,come-along, hydraulic device, etc. that can pull objects together orpush objects apart at a controlled rate and with sufficient force) istemporarily installed between the corresponding truss attachmentportions 154 a and 154 b. More specifically, in the illustratedembodiment the push/pull device 1210 includes a first clevis 1212 a onone end and a second clevis 1212 b on the opposite end. The clevises1212 are attached to the body of the push/pull device 1210 by threadedrods 1216 that can be drawn into the body of the push/pull device 1210or extended out of the body of the push/pull device 1210 by appropriateoperation of a manual actuator 1214 (e.g., a ratchet handle). Each ofthe clevises 1212 can be releasably attached to the corresponding trussattachment portion 154 by a temporary fastener 1218 (e.g., a bolt) thatextends through the clevis 1212 and the corresponding aperture 1202.After the push/pull device 1210 has been coupled to the opposing trussattachment portions 154, the actuator 1214 can be moved up and down inthe appropriate direction to ratchet the spar end portions 171 c and 171d together and/or apart as desired.

To join the first blade segment 116 a to the second blade segment 116 bin accordance with one embodiment of the disclosure, a second push/pulldevice (not shown) is operably coupled between the third and fourthtruss attachment members 150 c, 150 d on the first spar 170 a, and athird push/pull device (also not shown) is operably coupled between thefifth and sixth truss attachment members 150 e, 150 f on the third spar170 c, as described above with reference to the second spar 170 b. Thespars 170 are then simultaneously pulled together by operation of thethree push/pull devices 1210 to “dry fit” the end portions 171 andconfirm that they are properly aligned. After this has been done, thepush/pull devices 1210 are operated to separate the spar end portions171 so that the end portions 171 can be suitably prepared for bonding asdescribed in detail below.

Once the end portions 171 of the spars 170 have been fit checked asdescribed above, the overlapping surfaces of the projections/recesses174/175 (FIG. 10A) of the end portions 171 can be prepared for bonding.In a particular embodiment, the mating surfaces can be prepared forbonding by first sanding with an appropriate grade sandpaper, followedby a cleaning with acetone and/or a wipe with a lint-free cloth,followed by a wipe with isopropyl alcohol. A suitable adhesive (e.g.,epoxy, polyurethane, methyl methacrylate, and/or other adhesive) canthen be mixed and applied to the mating surfaces of the end portions171. Enough adhesive is applied to the mating surfaces to adequatelycover the zig-zag bond line. A localized or linear spacer made ofsuitable material can be laid on a surface of each spar 170 horizontalto the length of the spar. The end portions 171 of the spars 170 arethen pulled together simultaneously by individual actuation of the, e.g.three, push/pull devices 1210. As the end portions 171 move together,adhesive that squeezes out of the joint can be wiped away. In anotherarrangement, the blade assembler can first draw these end portions 171together, and then inject adhesive between overlapping projections andrecesses, as is described further in pending U.S. patent applicationSer. No. ______, titled “Segmented Wind Turbine Blades with TrussConnection Regions, and Associated Systems and Methods,” filedconcurrently herewith and previously incorporated by reference. Theoverlapping end portions 171 can then be clamped together with apressure enclosure tool as described in more detail below. After the endportions of the blade segments 116 have been suitably joined, the trussstruts (e.g., truss struts 143) can be installed in the bay between theribs 142 using, e.g., the apertures 1202 in the attachment members 150.After the diagonal truss struts have been attached to the bladesegments, the push/pull device(s) 1210 can be removed. The bladesegments 116 can then be prepared for installation of skin panels ontothe ribs 142.

FIG. 13 is a partially exploded, schematic isometric view of the jointbetween the first blade segment 116 a and the second blade segment 116 billustrating an apparatus and method for clamping and curing the jointend portions 171 of the spars 170 in accordance with an embodiment ofthe disclosure. In FIG. 13, the push/pull device(s) 1210 have beenremoved for purposes of clarity, but those of ordinary skill in the artwill understand that the push/pull device(s) 1210 can be left in placeduring the clamping and curing of the spar joints if desirable.

In the illustrated embodiment, a clamping assembly 1330 can include aclamping tool 1320 that includes at least two opposing plate portions1321 a, 1321 b that clamp inwardly on the joint between the engaged sparend portions 171 c, 171 d. The clamping tool 1320 applies adequatepressure to the joint during the adhesive curing process. The clampingtool 1320 can include manually operable clamping devices (e.g., such asC-clamps) and/or automatic clamping devices, such as hydraulic clamps.In addition, a vacuum blanket or bag 1322 can be wrapped around thejoint and evacuated to remove any air pockets from the adhesive bondline. Moreover, in one particular aspect of this embodiment, a heatingelement 1324 (e.g., an electro-thermal heating element) can also bepositioned locally around the joint to ensure proper curing of theadhesive at a suitable temperature for a suitable period of time (e.g.,24 hours). In the other embodiments, the heating element 1324, thevacuum bag 1322, and/or the clamping tool 1320 can be omitted, and thebonded joint can be positioned in an autoclave or other suitableapparatus for elevating the temperature and/or pressure of the joint toensure suitable curing of the adhesive. Although only a single clampingassembly 1330 is illustrated in FIG. 13 for purposes of clarity, it willbe understood that similar or equivalent pressure enclosure tools canalso be used to simultaneously cure the joints formed between the otherend portions 171 a, 171 b, 171 e, 171 f associated with the first spar170 a and the third spar 170 c. The methods and system described abovefor joining turbine blade spars together can also be used at the otherblade segment joints.

In other embodiments the spar 170 can be joined using techniques otherthan those described above with reference to FIGS. 11A-11E, for example,those disclosed in PCT Application US09/66875, previously incorporatedherein by reference. Still further techniques include, but are notlimited to the use of fasteners, bolts arranged in multiple directions,shear connecting tension bolts, scarf joints, butt joints and laminatedoverlays.

The foregoing process can be used to connect the first and second bladesegments, and then to connect the second and third blade segments. Theorder in which the process steps are completed can be changed in otherembodiments. For example, the second and third segments can be attachedto each other first, and then the first segment can be attached to thesecond segment. Once the spars 170 of adjacent blade segments areconnected, a section of skin 115 (FIG. 2) is laid up or otherwisepositioned over the joint to form a smooth continuous skin from oneblade segment to the next. The completed blade may then be attached to acrane or other suitable structure for lifting the blade, and each of thenow-attached segments can be decoupled from the corresponding supports123 shown in FIG. 10D. If necessary, the blade skin can be patched orotherwise treated to seal any temporary holes or openings necessitatedby the temporary connection to the supports 123. Once the blade isfinished, it can be lifted from the platforms and attached to the hub105 shown in FIG. 1. In another embodiment, the completed blade can bemoved from the assembly site to the wind turbine via one of thetransport devices described above, or via a different transport device,as described further below with reference to FIGS. 14A-14F.

FIGS. 14A-14F illustrate systems and methods for moving and assemblingwind turbine blade segments in accordance with further embodiments ofthe disclosure. Referring first to FIG. 14A, multiple blade segments maybe carried by a single transport device. For example, FIG. 14Aillustrates a first transport device 1421 a (e.g., a tractor-trailer riggenerally similar to those described above) having a first carrier 1480a that simultaneously supports multiple blade segments. In a particularembodiment shown in FIG. 14A, the multiple blade segments include onesecond blade segment 116 b, and two third blade segments 116 c. Thefirst carrier 1480 a can include two fixture elements 1481 that hold theblade segments in a fixed position relative to the first transportdevice 1421 a.

FIG. 14A also illustrates another first carrier 1480 a that supports twosecond blade segments 116 b and one third blade segment 116 c, inposition for transport by a first transport device 1421 a. FIG. 14Astill further illustrates additional first carriers 1480 a, each ofwhich supports one first blade segment 116 a. In a particularembodiment, the first blade segments 116 a are too large to allowmultiple blade segments to be carried on the same first transport device1421 a. Accordingly, each first blade segment 116 c is transportedindividually. The first carriers 1480 a positioned to carry the firstblade segments 116 a can include a corresponding fixture element 1481and an adjustment element 1482. The adjustment element 1482 allows thefirst blade segment 116 a to be rotated off-axis, as shown in FIG. 14A,so that is will fit under highway overpasses. The fixture element 1481holds the blade in this rotated configuration. Using the arrangementabove, five first transport devices 1421 a can be used to transport allnine blade segments used for a three-blade turbine.

In FIG. 14B, the first blade segment 116 a has been removed from thefirst transport device 1421 a. An operator has rotated the first bladesegment 116 a (as indicated by arrow R) under the guidance and controlof the adjustment element 1482, so that the blade now has a verticalposition. A new fixture element 1481 is then positioned beneath thefirst blade segment 116 a to support it in this new orientation.

Referring next to FIG. 14C, the second blade segment 116 b has beenremoved from the first transport device 1421 a (FIG. 14A) and placed ona second transport device 1421 b. The second transport device 1421 b caninclude a chassis 1422 carrying a positioning unit 1423. The positioningunit 1423 can include multiple wheels 1424 (e.g., four castor-typewheels are shown in FIG. 14C) outfitted with large, all-terrain tires1425. Accordingly, the second transport device 1421 b can be rolledalong the ground at an assembly site that has unpaved, unimproved oronly rudimentarily improved surfaces. The second transport device 1421 bcan further include a second carrier 1480 b that supports the secondblade segment 116 b. The second carrier 1480 b can include multipleupwardly projecting support members 1483, each of which carriers anengagement member 1484. In a particular embodiment, the individualengagement members 1484 include straps or other flexible tensionelements having attachment features 1485 (e.g., clips, hooks, buckles,or other suitable arrangements) that are releasably attached to thesecond blade segment 116 b. The engagement members 1484 are attached tothe corresponding support members 1483 with an adjustable arrangement,e.g., a releasable ratchet device.

In operation, an operator can adjust the axial position, lateralposition, and yaw angle of the second blade segment 116 b by rolling thesecond transport device 1480 b appropriately. The operator can adjustthe vertical position of the second blade segment 116 b by adjustingeach of the engagement members 1484 (e.g., by the same amount). Theoperator can adjust a rotation angle R1 (e.g., a roll angle) of thesecond blade segment 116 b relative to a first axis A1 by adjusting theengagement members 1484 on one side of the first axis A1 by a differentamount than the engagement members 1484 on the other side of the firstaxis A1. The operator can adjust a transverse rotation angle R2 (e.g., apitch angle) of the second blade segment 116 b relative to a second(transverse) axis A2 by adjusting fore and aft engagement members 1484by different amounts. When the second blade segment 116 b has the properorientation relative to the first blade segment 116 a, the operator canroll the second transport device 1421 b toward the first blade segment116 a as indicated by arrow T1 to align the ends of the spars 170 a-170c carried by each of the first and second blade segment 116 a, 116 b.The foregoing operations can be completed manually, or via powereddrivers (e.g., motors) or other devices.

In FIG. 14D, the second transport device 1421 b has been removed, andthe second blade segment 116 b is now supported by fixtures 1481 thatcarry the second blade segment 116 b in the proper position at theassembly site. The second blade segment 116 b has been attached to thefirst blade segment 116 a by connecting the ends of the correspondingspars 170 a-170 c, adding a rib 142, and adding truss members 143 at theconnection location. Further details of an arrangement for carrying outthis process are disclosed in pending U.S. application Ser. No. ______,titled “Segmented Wind Turbine Blades with Truss Connection Regions, andAssociated Systems and Methods,” and previously incorporated herein byreference.

In FIG. 14E, a process generally similar to that described above withreference to FIGS. 14C and 14D is conducted to attach the third bladesegment 116 c to the second blade segment 116 b. As discussed above, theoverall blade 110 may be curved so that the axes along which the secondand third blade segments 116 b, 116 c are attached may be different thanthe axes along which the first and second blade segments 116 a, 116 bare attached. Because the second transport device 1480 b is easilymovable, the operator can use the same or a generally similar secondtransport device 1480 b to move the third blade segment 116 c toward thesecond blade segment 116 b. Accordingly, the operator can adjust thevertical position of the third blade segment 116 c, as well as arotation angle R3 relative to a third (longitudinal) axis A3, and arotation angle R4 relative to a fourth (transverse) axis A4. Theoperator can then move the third blade segment 116 c via the secondtransport device 1480 b toward the second blade segment 116 b, asindicated by arrow T3, and connect the two segments 116 b, 116 c usingany of the techniques described above.

FIG. 14F illustrates the assembled blade 110, with a tip section 116 dattached to the third blade segment 116 c. In a particular embodiment,the assembled blade 110 can now be repositioned on the first transportdevice 1421 a with a significant portion of the blade 110 overhangingthe first transport device 1421 a. While this arrangement would not besuitable for transporting the blade over typical highways, it can beused to transport the blade 110 from an assembly site (e.g., located ata wind farm) to a particular wind turbine (also located at the windfarm). Accordingly, the first transport device 1421 a can be driven atvery low speed over improved or unimproved roads (e.g., at the windfarm) having gradual radiuses of curvature, without damaging the windturbine blade 110 or structures along the way. Typically, the transportdistances and speeds associated with moving the assembled blade from theassembly site to the wind turbine will be less (e.g., significantlyless) than the distances and speeds associated with transporting theindividual blade segments to the assembly site.

One feature of an embodiment described above with reference to FIGS.14A-14F is that the blade segments 116 can be assembled at an unimprovedassembly site (which may be typical at a wind farm) without impactingthe accuracy which with the blade segments 116 are attached. Thisprocess can be conducted economically by using fewer first transportdevices 1480 a to transport the blade segments 116 to the site, and/orby using a single second transport device 1480 b to sequentiallyassemble multiple blade segments. Still another feature of at least someof the foregoing embodiments is that the assembled blade can betransported from the assembly site to the wind turbine using a standardfirst transport device 1480 a (e.g., an over-the-highway tractor-trailerrig), even though the assembled blade 110 is over-length (by 50%, 60%,70%, or another significant amount), and even though the road betweenthe assembly site and the wind turbine may not be up to the standards ofa typical highway.

Another feature of several of the foregoing embodiments is that theblade segments can be easily transported from one or more manufacturingfacilities to an installation site using conventional transport systemse.g., highway trucks, trains, or barges. Because the blade is segmented,it is easier to transport than it would be if it were completelyassembled at the manufacturing site. In addition, the transportplatforms can include guide structures that accurately align each of theblade segments relative to neighboring segments to facilitate accurateand repeatable assembly techniques. This in turn can produce moreuniform blades, despite the fact that the blades are segmented. As aresult, the blades can operate more efficiently when installed oncorresponding wind turbines, and can reduce maintenance costs over thelife-time of the blades.

From the foregoing, it will be appreciated that specific embodimentshave been described herein for purposes of illustration, but thatvarious modifications may be made without deviating from the presentdisclosure. For example, the guide structures described above may havearrangements other than nested portions that are each movable along asingle axis. The guide structures may include features other thanrollers to control the motion of the supports relative to each other. Inanother embodiment, the guide structure can be configured to facilitaterestricted rotational motion, in addition to restricted linear motion.The supports can have other arrangements, including arrangements inwhich the supports extend above the blade and straddle the blade, withthe blade supported (e.g., suspended) from above. In still furtherembodiments, not all the transport platforms 121 provide axial motionfor the corresponding blade segment. For example, the second bladesegment 116 b can have a fixed axial position relative to the secondtransport platform 121 b, and the first and third segments 116 a, 116 ccan move toward opposing ends of the centrally located second segment116 b. While FIG. 3 illustrates two supports 123 for each blade segment,in other embodiments, the guide structure 122 can include otherarrangements, including a single support 123 at each transport platform121, or more than two supports 123 at each transport platform 121. Thewind turbine blades can have structures other than those expresslydisclosed herein, but can still be transported, aligned and/or assembledusing the systems and methods described above. For example, in otherembodiments these methods and systems can be used to join turbine bladestructures together that extend in chordwise directions. In stillfurther embodiments, these methods and systems can be used to joinleading or trailing edge members together, or to join portions of asegmented root together.

Certain aspects of the disclosure described above in the context ofparticular embodiments may be combined or eliminated in otherembodiments. For example, the motorized or otherwise powered actuatorsdescribed in the context of providing lateral and axial motion may beapplied to vertical motion in particular embodiments. The carriers andguide structures described in the context of the first transport devices121, 1421 a may be combined with the second transport device 1421 b inparticular embodiments. Further, while advantages associated withcertain embodiments have been described in the context of thoseembodiments, other embodiments may also exhibit such advantages. Not alladvantages need necessarily exhibits such advantages to follow withinthe scope of the present disclosure. Accordingly, the disclosure andassociated technology can encompass other embodiments not expresslyshown or described herein.

1. A system for assembling spanwise segments of a wind turbine blade,comprising: a first transport device being movable as a unit from ablade fabrication site to a blade assembly site, the first transportdevice having a first carrier positioned to carry a first spanwisesegment of a wind turbine blade with the first segment aligned along afirst blade axis; a second transport device being movable as a unit froma blade fabrication site to the blade assembly site, the secondtransport device having a second carrier positioned to carry a secondspanwise segment of a wind turbine blade with the second segment alignedalong a second blade axis; and a guide structure carried by at least oneof the first and second transport devices, the guide structure beingcoupled between the at least one transport device and a correspondingone of the carriers, the guide structure having a motion path alignedwith a corresponding one of the first and second blade axes, the guidestructure being positioned to guide the corresponding carrier along themotion path toward the other of the first and second transport devices.2. The system of claim 1 wherein the guide structure is positioned toguide the corresponding carrier in a linear manner.
 3. The system ofclaim 1 wherein the first and second transport devices are wheeled. 4.The system of claim 3 wherein the first and second transport devicesinclude corresponding highway truck trailers.
 5. The system of claim 1,further comprising a drive mechanism carried by at least one of thefirst and second transport devices, the drive mechanism being positionedto drive at least one of the first and second carriers relative to theother along the guide path.
 6. The system of claim 1 wherein the guidestructure includes a base portion carried by the first transport device,a first portion carried by the base portion and movable relative to thebase portion along a restricted first motion path, and a second portioncarried by the first portion and movable relative to the first portionalong a restricted second motion path, transverse to the first motionpath.
 7. The system of claim 6 wherein the second portion includes aroller assembly that is movable relative to the first portion and thatis releasably engaged with the first carrier.
 8. The system of claim 6wherein the first portion includes a first roller assembly that isengaged with the base and rollable relative to the base along the firstmotion path, and wherein the second portion includes a second rollerassembly that is engaged with the first portion and rollable relative tothe first portion along the second motion path.
 9. The system of claim6, further comprising: a first driver operatively coupled between thebase and the first portion to move the first portion relative to thebase; and a second driver operatively coupled between the first portionand the second portion to move the second portion relative to the firstportion.
 10. The system of claim 6 wherein the base includes an axialguide, and wherein the first portion includes a roller assembly, andwherein the roller assembly include a first, load-bearing rollerpositioned to rotate about a generally horizontal axis, and a second,guide roller positioned to rotate about a non-horizontal axis.
 11. Thesystem of claim 1 wherein the guide structure is a first guide structurepositioned between the first transport device and the first carrier, thefirst carrier being movable along the first blade axis, and wherein thesystem further comprises a second guide structure positioned between thesecond transport device and the second carrier, the second carrier beingmovable along the second blade axis.
 12. The system of claim 1, furthercomprising: a driver device operatively coupled to the guide structureto move the corresponding carrier along the motion path; a sensorpositioned to sense a location of the carrier; and a controlleroperatively coupled to the driver device and the sensor, the controllerbeing programmed with instructions that, when executed, automaticallyactivate the driver to move the carrier in response to a signal receivedfrom the sensor.
 13. A system for assembling spanwise segments of a windturbine blade, comprising: a transport device; an all-terrainpositioning unit depending from the transport device and activatable tomove the transport device along a first axis; a carrier supported by thetransport device, the carrier being positioned to support aspanwise-extending wind turbine blade segment; and multiple engagementmembers depending from the carrier, with individual engagement membersreleasably connectable to the blade segment, and movable relative to thecarrier to adjust a vertical position of the blade segment, a firstrotation angle of the blade segment relative to the first axis, and asecond rotation angle of the blade relative to a second axis transverseto the first axis.
 14. The system of claim 13 wherein the positioningunit includes four all-terrain tires.
 15. The system of claim 13 whereinthe multiple engagement members include four engagement members, andwherein individual engagement members include a flexible tension member.16. The system of claim 13 wherein the carrier includes multiple uprightsupport members, and wherein the multiple engagement members includefour engagement members, and wherein each engagement member includes aflexible strap having an adjustable length portion between the carrierand the blade segment.
 17. A method for assembling spanwise segments ofa wind turbine blade, comprising: transporting a first assembledspanwise segment of a wind turbine blade as a unit from a bladefabrication site to a blade assembly site while the first blade segmentis carried by a first transport device; transporting a second assembledspanwise segment of a wind turbine blade as a unit from a bladefabrication site to the blade assembly site while the second bladesegment is carried by a second transport device; at the blade assemblysite, moving at least one of the first and second blade segmentsrelative to the other along a restricted guide path, while the firstblade segment is carried by the first transport device and the secondblade segment is carried by the second transport device; connecting thefirst and second blade segments to each other while the first bladesegment is carried by the first transport device and the segment bladesection is carried by the second transport device; separating theconnected first and second blade segments from the first and secondtransport devices; and mounting the first and second blade segments as aunit to a wind turbine.
 18. The method of claim 17 wherein separatingthe first and second blade segments from the first and second transportdevices includes: disengaging the second blade segment from the secondtransport device while the connected first and second blade segments arecarried by the first transport device; carrying the connected first andsecond blade segments from the assembly site to the wind turbine withthe first transport device; and removing the connected first and secondblade segments as a unit from the first transport device.
 19. The methodof claim 17 wherein transporting the first assembled spanwise segment ofthe wind turbine blade includes transporting the first segment via afirst over-the-road truck-drawn trailer, and wherein transporting thesecond assembled spanwise segment of the wind turbine blade includestransporting the second segment via a second over-the-road truck-drawntrailer.
 20. The method of claim 17, further comprising moving at leastone of the first and second blade segments relative to the correspondingtransport device and relative to the other blade segment at the assemblysite prior to connecting the first and second blade segments.
 21. Themethod of claim 20 wherein moving at least one of the first and secondblade segments relative to the other includes moving the at least oneblade segment along a linear axis while restricting or preventing motionof the at least one blade segment transverse to the linear axis.
 22. Themethod of claim 20 wherein moving at least one of the first and secondblade segments relative to the other includes moving the at least oneblade segment along motion path that includes components in twoorthogonal directions.
 23. The method of claim 20 wherein moving atleast one of the first and second blade segments relative to the otherincludes connecting a pulling device between the first and second bladesegments and drawing the at least one blade segment toward the otherwith the pulling device.
 24. The method of claim 17 wherein transportingthe first assembled spanwise segment includes transporting the firstassembled spanwise segment with a carrier while the carrier has a fixedposition relative to the first transport device, and wherein the methodfurther comprises removably positioning a guide structure between thecarrier and the first transport device prior to moving the first bladesegment, and wherein moving at least one of the first and second bladesegments relative to the other along a restricted guide path includesmoving the first blade segment along a restricted guide path establishedby the guide structure.
 25. The method of claim 17 wherein carrying thefirst blade segment includes carrying multiple assembled blade segmentswith the first transport device.
 26. The method of claim 17 whereintransporting a first assembled spanwise segment of a wind turbine bladeincludes transporting the first segment from a first fabrication site,and wherein transporting a second assembled spanwise segment of a windturbine blade includes transporting the second segment from a secondfabrication site.
 27. A method for assembling spanwise segments of awind turbine blade, comprising: transporting a first assembled spanwisesegment of a wind turbine blade as a unit on a surface road from a bladefabrication site to a blade assembly site while the first blade segmentis supported by a first carrier that is in turn supported by a firsttruck-drawn trailer; transporting a second assembled spanwise segment ofa wind turbine blade as a unit on a surface road from a bladefabrication site to the blade assembly site while the second bladesegment is supported by a second carrier that is in turn supported by asecond truck-drawn trailer; transporting a third assembled spanwisesegment of a wind turbine blade as a unit on a surface road from a bladefabrication site to the blade assembly site while the third bladesegment is supported by a third carrier that is in turn supported by athird truck-drawn trailer; at the assembly site, aligning the first andsecond truck-drawn trailers relative to each other, while the firstblade section is carried by the first truck-drawn trailer and the secondblade section is carried by the second truck-drawn trailer; at theassembly site, aligning the first and second carriers relative to eachother, while the first blade section is carried by the first truck-drawntrailer and the second blade section is carried by the secondtruck-drawn trailer; moving at least one of the first and secondcarriers relative to the other along a restricted motion path toposition the first and second spanwise segments adjacent to each other;connecting the first and second blade segments to each other while thefirst blade segment is carried by the first truck-drawn trailer and thesecond blade segment is carried by the second truck-drawn trailer;moving at least one of the second and third carriers relative to theother along a restricted motion path to position the second and thirdspanwise segments adjacent to each other; connecting the second andthird blade segments to each other while the second blade segment iscarried by the second truck-drawn trailer and the third blade segment iscarried by the third truck-drawn trailer; removing the first, second andthird blade segments from the first, second and third truck-drawntrailers; and mounting the first, second and third blade segments as aunit to a wind turbine.
 28. The method of claim 27 wherein connectingthe first and second blade segments includes: aligning a first spar endportion of the first blade segment with a second spar end portion of thesecond blade segment; aligning a third spar end portion of the firstblade segment with a fourth spar end portion of the second bladesegment; and moving the first spar end portion toward the second sparend portion and the third spar end portion toward the fourth spar endportion to connect the first spar end portion to the second spar endportion and connect the third spar end portion to the fourth spar endportion.
 29. The method of claim 28 wherein the first and second endspar portions include staggered layers of material that form anon-monotonically varying bond line when the two end spar portions areconnected.
 30. The method of claim 28, further comprising temporarilycoupling a compressing device between the first spanwise segment and thesecond spanwise segment, wherein moving the first spar end portiontoward the second spar end portion and the third spar end portion towardthe fourth spar end portion includes acuating the compressing device todraw the first spanwise segment and the second spanwise segmenttogether.
 31. A method for assembling spanwise segments of a windturbine blade, comprising: transporting a first assembled spanwisesegment of a wind turbine blade as a unit to a blade assembly site;transporting a second assembled spanwise segment of a wind turbine bladeas a unit to the blade assembly site; at the assembly site, connectingthe first and second segments to each other; carrying the first andsecond segments with a transport device; transporting the connectedfirst and second segments as a unit from the assembly site to a windturbine, with the transport device; removing the connected first andsecond segments, as a unit, from the transport device; and installingthe connected first and second segments, as a unit, to the wind turbine.32. The method of claim 31 wherein transporting a first segment includestransporting the first segment while the first segment is carried by afirst transport device, and wherein transporting a second segmentincludes transporting the second segment while the second segment iscarried by a second transport device, and wherein connecting the firstand second segments includes connecting the first and second segmentswhile the first segment is carried by the first transport device and thesecond segment is carried by the second transport device, and whereintransporting the connected first and second segments includestransporting the connected first and second segments with the firsttransport device and not the second transport device.
 33. The method ofclaim 31 wherein transporting a first segment includes transporting thefirst segment over a first distance and at a first average rate, andwherein transporting the second segment includes transporting the secondsegment over a second distance and at a second average rate, and whereintransporting the connected first and second segments includestransporting the connected first and second segments over a thirddistance less than each of the first and second distances, and at athird average rate less than each of the first and second average rates.34. The method of claim 31 wherein the connected first and secondsegments have a connected segment length, and wherein transporting theconnected first and second segments as a unit includes transporting theconnected first and second segments with at least 50% of the connectedsegment length cantilevered relative to the first transport device. 35.A method for assembling spanwise segments of a wind turbine blade,comprising: transporting a first assembled spanwise segment of a windturbine blade as a unit to a blade assembly site; transporting a secondassembled spanwise segment of the wind turbine blade as a unit to theblade assembly site; carrying at least the second segment with atransport device at the assembly site; rolling the transport device overrough terrain at the assembly site to position the second segmentadjacent to the first segment; connecting the first and second segmentsto each other at the assembly site; installing the connected first andsecond segments, as a unit, on a wind turbine.
 36. The method of claim35, further comprising transporting the connected first and secondsegments as a unit from the assembly site to the wind turbine.
 37. Themethod of claim 35: wherein carrying the second segment includessupporting the second segment at four different locations with fourindependently adjustable engagement members; wherein rolling thetransport device includes rolling the transport device over unpavedterrain to adjust an axial position, lateral position, and yaw angle ofthe second segment; and wherein the method further comprises: adjustingthe engagement members to adjust a height of the second segment;adjusting the engagement members to adjust a pitch angle of the secondsegment relative to the ground; and adjusting the engagement members toadjust a roll angle of the second segment relative to the ground. 38.The method of claim 35 wherein carrying the second blade segmentincludes suspending the second blade segment from four independentlyadjustable engagement members.